Got Weeds?

By Priscilla Stevens

 

Committing to eliminating toxic herbicides on our lawns may seem overwhelming. If we are accustomed to using chemical pre-emergents and sprays to control unwanted growth, we may balk at the thought of least toxic alternatives, as they may seem more cumbersome to use. The payoff is a healthier environment. Popular chemical herbicides are dangerous to human health and are definitely unwanted chemicals in our sensitive watershed community. The herbicide 2-4D is widely used to control dandelion, violet and wild strawberry growth in our shady lawns. The Material Safety Data Sheet for 2-4D clearly states that this should not be used in areas which drain into bodies of water, as it can contaminate ground water.

The American Plant Food Co. in Bethesda Md. Suggests the following preventative methods for dealing with weeds in the lawn.

  • Limestone: Regular applications of granular lime will keep the pH of the soil in the proper range, between 6 and 7. Many of our more prevalent weeds thrive only in more acidic soil. By raising the pH, this may be the most cost effective and least expensive step toward fewer weeds in the lawn.
  • Fertilization: Use an organic, slow release fertilizer in the fall. The weeds cannot compete with a dense lawn.
  • Seeding: Thin areas or bare spots are invitations for weeds to grow. Seeding or over seeding (best time is in the fall) is necessary to maintain a dense turf.
  • Watering: Turf grass thrives on 1" of rain or water per week. This encourages strong root development. It is actually better to water deeply once a week, rather than to water frequently for short periods of time.
  • Mowing height: During the summer months, change the mowing height to 3". Taller grass helps shade out sun loving weeds, and keeps the roots cooler and able to hold more moisture.
  • Corn Gluten: This is used as a pre-emergent weed control. When applied in early spring, about the same time as the forsythia blooms, it acts against a wide range of weed seeds before the seeds germinate. (See www.lakebarcroft.org for more information about corn gluten.)

Other controls:

  • Physical approaches: Mulching, mowing, string trimmers, spading, hoeing and pulling up weeds are other ways to avoid herbicides.
  • Flamers; Propane torches with a fan tip designed for garden use – work best on weeds that are less than 2 inches tall. It is a fast effective way to control weeds along fence lines, in sidewalks, driveways, patios, or other paved areas.
  • Hot Water: If you can boil water, you can have power to create an effective weed-killing spray. While not practical for large areas it is an alternative to flaming or hand weeding. Please note that hot water also destroys soil organisms for several weeks, so this is not a desirable method in a garden area.

Consider making your own inexpensive and safe alternative vegetation killer, as is suggested in the book Better Basics for the Home:

CHEAP AND SAFE NORTH DAKOTA VEGETATION KILLER

This preparation is for weeds growing in sidewalk cracks and between bricks, not in the garden.

1 cup salt
8 drops liquid detergent
1 gallon vinegar

Combine the ingredients in a 2-gallon pail. Stir to blend. Pour some of the mixture into a spray bottle and spray weeds. The salt will kill all the vegetation, so don't use this in a vegetable garden. Makes one gallon and keeps indefinitely.

PRE-EMERGENT DRY METHOD

We have learned from personal experience that you can eliminate vegetation on a brick patio.

In early Spring, brush regular table salt into cracks and crevices of the patio using a wide push broom. A 4-pound box will cover a 25 square foot area. Properly swept, the salt is not noticeable as it is forced into the cracks discouraging germination of seeds. This may have to be repeated once in the fall.

RESOURCES:

  • American Plant Food Co. Garden Center and Nursery - Bulletin #96 Preventing Weeds in the Lawn
  • U.S. Fish and Wildlife Service Homeowner's Guide to Protecting Frogs <www.fws.gov>
  • Controlling Weeds - Rodale's Successful Organic Gardening - Rodale Press
  • Better Basics for the Home - Annie Berthold -- Bond, Three Rivers Press